The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 18, 2003
Filed:
Aug. 07, 2001
Robert A. Beach, Altadena, CA (US);
Robert P. Strittmatter, Pasadena, CA (US);
Thomas C. McGill, Pasadena, CA (US);
California Institue of Technology, Pasadena, CA (US);
Abstract
An integrated microsensor includes a bowed micromachined membrane coupled to a substrate to define a microcavity therebetween. An integrated strain sensor is coupled to the micromachined membrane to generate a signal responsive to (deformation of the membrane and hence responsive to the pressure of the fluid in the microcavity. A frame is coupled to the peripheral edge of the membrane to assist in enlarging the microcavity. The membrane is composed of a nitride of B, Al, Ga, In, Tl or combinations thereof, or more particularly of p-type GaN where the frame is comprised of n-type GaN. The membrane and frame are fabricated using a photoelectrochemical etching technique. The fabrication of the integrated strain sensor creates stresses across the membrane. The strain sensor comprises an integrated circuit strain-FET. The strain-FET comprises an AlGaN/GaN heterostructure having an AlGaN/GaN interface where deformation of the membrane is coupled as strain to the AlGaN/GaN piezoelectric interface.